Automatic dispensers of various types are used to dispense a broad range of products, including, without limitation, towels, tissues, wipes, sheet-form materials, soap, shaving cream, fragrances and personal care products. Automatic dispensers include certain controls provided to make one or more aspects of dispenser operation automatic.
Many dispensers include a proximity detector used to detect a user proximate the dispenser and to trigger dispenser operation without direct contact between the user and the dispenser. These types of dispensers are frequently referred to as “touchless” or “hands free” dispensers. One advantage of a hands-free dispenser is that transfer of soil or germs from the dispenser to the user is limited. Limiting contact between the user and the dispenser may also contribute to a more attractive dispenser. Proximity detectors are useful in applications other than dispensers wherein it is desired to control a device.
The dispenser must operate reliably over many dispensing cycles. The proximity detector used to control dispenser operation must accurately detect a user and should discriminate against false detections. The dispenser and proximity detector should operate consistently under a variety of different conditions, for example conditions of fluctuating humidity. There is a need for improvement in these and other aspects of automatic dispenser and proximity detector design and operation.